The average operation cycle time is the key data in labor costing and production scheduling in apparel manufacturing. The average operation cycle time tells the company’s performance story. In this article, I will walk you through why this statement is true.
I have visited several garment factories where I have closely worked with industrial engineers. I have met the owners of these garment factories. I am happy to say that all the factory management and factory owners like the IE tools used by their IE team. They trust the standard time established by their IE team.
From the discussion with a couple of factory owners, I observed that they believe more on the average cycle time of the sewing operations than the standard time established through software or using the Time Study method. The reasons are subjective.
How to calculate average cycle time?
Here the average cycle time can be measured in two ways –
Table-1: Average Cycle time calculation from single days data
In Table-2, Average cycle time is calculated from day-1 production to the current day of production of the same order. This gives a more accurate average cycle time or each operation.
Table-2: Average Cycle time calculation from a couple of days of production
Normally, industrial engineers establish garment operation SAM considering standard situations – but factories can’t standardize the workstation, and operations as quickly as you establish the SAM.
What is the use of SAM time, if the average operation cycle time is 3-5 times higher than the standard operation SAM? Can you imagine, what would the line efficiency, when garment SAM is 5 times lower than the average cycle time? – resulted in line efficiency would be near to 10%. The factory will not achieve anything by showing its line performance 10-20% efficiency at its pick production.
Consider the case where the factory’s maximum line efficiency is 20%. This not due to the low skill of the operators or not due to a huge loss-time. This is because the standard time is established considering a standard working environment. The allowances added are not taken from the factory data. Instead, theoretical allowances are considered. There are some product categories (Jackets, coats), which need a lot of material handling time. On the other side, some factories produce basic garments and large order volumes. In such plants, allowances would be minimum.
When the production planning and labor cost estimation are done with this SAM (very tight or very loose SAM), you will not get the accurate labor costing data and expected production completion date. The average cycle time gives a better idea for production scheduling and production planning. I have seen factories still consider the average cycle time for garment costing and production scheduling, though their IEs establish garment SAM and do all line layout planning and machine requirements from operation bulletin.
There are many garment factories that don’t have a standard time for the operations and task their employees perform on the shop floor. To them finding the average operation cycle time is key data for production planning and estimating piece rate.
Factory owners are comfortable with the average cycle time. The reason, they can measure it and the average cycle time is what they can achieve. Standard time can be considered as a target for the employees what they should try to achieve.
- Calculating average operation cycle time through observation and time study
- Capture total hours worked in the operation in a day and divide it by a total number of garments produced.
Let me explain how the average operation cycle time is calculated using the second method. In Table-1, I have shown the calculation of the average operation cycle for a single day. Employee-wise daily production is counted, and total working is taken from shift hours.
Average cycle time = (Total worked minutes/total pieces produced).
In the example, I have considered 8 hours for hours worked. To get a more accurate cycle time, capture operation-wise daily production quantity. Then capture all the loss-time and idle time of individual employees. Then calculate hours worked after deducting loss-time and waiting time from shift hours. In another word, you need to consider only the standard hours worked time for calculating average operation cycle time.
Table-1: Average Cycle time calculation from single days data
Date
|
Style
|
Employee
|
Operation
|
Produced Quantity
|
Hours Worked
|
Average Cycle time
|
11-02-19
|
Style-1
|
E-1001
|
Operation-1
|
186
|
8.00
|
2.58
|
11-02-19
|
Style-1
|
E-1002
|
Operation-2
|
983
|
8.00
|
0.49
|
11-02-19
|
Style-1
|
E-1003
|
Operation-3
|
799
|
8.00
|
0.60
|
11-02-19
|
Style-1
|
E-1004
|
Operation-4
|
177
|
8.00
|
2.71
|
11-02-19
|
Style-1
|
E-1005
|
Operation-5
|
192
|
8.00
|
2.50
|
11-02-19
|
Style-1
|
E-1006
|
Operation-6
|
968
|
8.00
|
0.50
|
11-02-19
|
Style-1
|
E-1007
|
Operation-7
|
559
|
8.00
|
0.86
|
11-02-19
|
Style-1
|
E-1008
|
Operation-8
|
555
|
8.00
|
0.86
|
11-02-19
|
Style-1
|
E-1009
|
Operation-9
|
274
|
8.00
|
1.75
|
11-02-19
|
Style-1
|
E-1010
|
Operation-10
|
282
|
8.00
|
1.70
|
In Table-2, Average cycle time is calculated from day-1 production to the current day of production of the same order. This gives a more accurate average cycle time or each operation.
Table-2: Average Cycle time calculation from a couple of days of production
Date
|
Style
|
Employee Code
|
Operation
|
Produced Quantity
|
Hours Worked
|
11-02-19
|
Style-1
|
E-1003
|
Operation-3
|
799
|
8
|
12-02-19
|
Style-1
|
E-1003
|
Operation-3
|
801
|
8
|
13-02-19
|
Style-1
|
E-1003
|
Operation-3
|
772
|
8
|
14-02-19
|
Style-1
|
E-1003
|
Operation-3
|
689
|
8
|
15-02-19
|
Style-1
|
E-1003
|
Operation-3
|
831
|
8
|
17-02-19
|
Style-1
|
E-1003
|
Operation-3
|
771
|
8
|
18-02-19
|
Style-1
|
E-1003
|
Operation-3
|
799
|
8
|
19-02-19
|
Style-1
|
E-1003
|
Operation-3
|
809
|
8
|
20-02-19
|
Style-1
|
E-1003
|
Operation-3
|
795
|
8
|
21-02-19
|
Style-1
|
E-1003
|
Operation-3
|
823
|
8
|
22-02-19
|
Style-1
|
E-1003
|
Operation-3
|
815
|
8
|
24-02-19
|
Style-1
|
E-1003
|
Operation-3
|
832
|
8
|
25-02-19
|
Style-1
|
E-1003
|
Operation-3
|
906
|
8
|
26-02-19
|
Style-1
|
E-1003
|
Operation-3
|
869
|
8
|
27-02-19
|
Style-1
|
E-1003
|
Operation-3
|
647
|
8
|
Total
|
11958
|
120
|
|||
Average Cycle Time (Total Hours worked x 60/Total
production)
|
0.60
Minutes
|
||||
Why factory owners are more interested in operation cycle time?
To establish standard time various allowances added to the cycle time, operator rating applied to the cycle time, other technical data and calculations are too complicated and sometimes do not seem real in the factory environment. Sometimes it has been observed that calculated standard time is too high compared to average operation cycle time. At the same time in other factories, the standard time is too low compared to the operation cycle time.Normally, industrial engineers establish garment operation SAM considering standard situations – but factories can’t standardize the workstation, and operations as quickly as you establish the SAM.
What is the use of SAM time, if the average operation cycle time is 3-5 times higher than the standard operation SAM? Can you imagine, what would the line efficiency, when garment SAM is 5 times lower than the average cycle time? – resulted in line efficiency would be near to 10%. The factory will not achieve anything by showing its line performance 10-20% efficiency at its pick production.
Consider the case where the factory’s maximum line efficiency is 20%. This not due to the low skill of the operators or not due to a huge loss-time. This is because the standard time is established considering a standard working environment. The allowances added are not taken from the factory data. Instead, theoretical allowances are considered. There are some product categories (Jackets, coats), which need a lot of material handling time. On the other side, some factories produce basic garments and large order volumes. In such plants, allowances would be minimum.
When the production planning and labor cost estimation are done with this SAM (very tight or very loose SAM), you will not get the accurate labor costing data and expected production completion date. The average cycle time gives a better idea for production scheduling and production planning. I have seen factories still consider the average cycle time for garment costing and production scheduling, though their IEs establish garment SAM and do all line layout planning and machine requirements from operation bulletin.
There are many garment factories that don’t have a standard time for the operations and task their employees perform on the shop floor. To them finding the average operation cycle time is key data for production planning and estimating piece rate.
Conclusion
The methods and formula are good for establishing garment standard time. I agree that factories must use the standard time to set-up the system, improving the working method and improving factor performance. With the standard methods and standard allowance percentage, factories must consider their factory standards, product categories, and equipment. Average cycle time measured through observing operators doing the job on the shop floor gives us a better idea for planning and managing the WIP and daily expected production. This article is written to make the factories aware that SAM is not all that you need to manage orders. You can take the help of cycle time for production planning and labor costing, even you don’t use SAM.Factory owners are comfortable with the average cycle time. The reason, they can measure it and the average cycle time is what they can achieve. Standard time can be considered as a target for the employees what they should try to achieve.